Several important epidemiological questions regarding the distribution and determinants of MERS-CoV infection in humans arise:

• As of March 1st 2014, nearly 2 years after MERS-CoV was first discovered, there have been a total of 180 cases of MERS-CoV infection with a 46% mortality rate reported worldwide to the WHO. All cases have had links to the Middle East, and the majority of cases (151 with 62 deaths (41% mortality) have been reported from KSA as of March 5, 2014. Does MERS-CoV only affect populations in the Middle East or is it also prevalent in countries in Africa, Asia, Australia and South America where camels are present?

• Does this focus on the Middle East represent a bias in case detection due to a high degree of awareness and governments having a more proactive screening programme for MERS-CoV?

• Is there evidence of association with the genetic make-up of Middle Eastern populations that would make people more or less susceptible to infection with MERS-CoV, as reported for other infectious diseases (Blackwell et al. 2009; Apps et al. 2013)?

• What role does co-infection with other respiratory disease pathogens play in clinical presentations of MERS-CoV (Rizzo et al. 2010; Redford et al. 2014)?

• When was MERS-CoV actually introduced into human populations and how did it cross the species barrier?

During the 2012 and 2013 Hajj pilgrimages, 5 million pilgrims from 184 countries (including 500 000 from African countries) visited Makkah and Madinah in KSA, and no cases of MERS-CoV were detected during their stay in KSA or after the pilgrims returned home.

As both camels and bats are found in all parts of Africa, there is a high likelihood of MERS-CoV infections being missed. There is certainly a lack of awareness of MERS-CoV across the African continent and beyond the Middle East amongst healthcare workers.

Furthermore, diagnostic services for respiratory viral infections are virtually non-existent at most entry points in the health system and are scanty at referral centres.

This certainly seems to document Dr. Memish's argument that the Arab nations, and Saudi Arabia in particular, are reporting MERS because no one else is seriously looking for it. He may be right, and it might be helpful if the KSA and Gulf states used some of their vast wealth to support a major surveillance effort—not only of camels and bats, but of humans.

Several important epidemiological questions regarding the distribution and determinants of MERS-CoV infection in humans arise:

• As of March 1st 2014, nearly 2 years after MERS-CoV was first discovered, there have been a total of 180 cases of MERS-CoV infection with a 46% mortality rate reported worldwide to the WHO. All cases have had links to the Middle East, and the majority of cases (151 with 62 deaths (41% mortality) have been reported from KSA as of March 5, 2014. Does MERS-CoV only affect populations in the Middle East or is it also prevalent in countries in Africa, Asia, Australia and South America where camels are present?

• Does this focus on the Middle East represent a bias in case detection due to a high degree of awareness and governments having a more proactive screening programme for MERS-CoV?

• Is there evidence of association with the genetic make-up of Middle Eastern populations that would make people more or less susceptible to infection with MERS-CoV, as reported for other infectious diseases (Blackwell et al. 2009; Apps et al. 2013)?

• What role does co-infection with other respiratory disease pathogens play in clinical presentations of MERS-CoV (Rizzo et al. 2010; Redford et al. 2014)?

• When was MERS-CoV actually introduced into human populations and how did it cross the species barrier?

During the 2012 and 2013 Hajj pilgrimages, 5 million pilgrims from 184 countries (including 500 000 from African countries) visited Makkah and Madinah in KSA, and no cases of MERS-CoV were detected during their stay in KSA or after the pilgrims returned home.

As both camels and bats are found in all parts of Africa, there is a high likelihood of MERS-CoV infections being missed. There is certainly a lack of awareness of MERS-CoV across the African continent and beyond the Middle East amongst healthcare workers.

Furthermore, diagnostic services for respiratory viral infections are virtually non-existent at most entry points in the health system and are scanty at referral centres.

This certainly seems to document Dr. Memish's argument that the Arab nations, and Saudi Arabia in particular, are reporting MERS because no one else is seriously looking for it. He may be right, and it might be helpful if the KSA and Gulf states used some of their vast wealth to support a major surveillance effort—not only of camels and bats, but of humans.